The mission of the Microscopy and Histopathology Core B is to provide access to basic and cutting-edge optical and electron microscopy equipment, expertise and methods for microscopy techniques, training, service, and histology/histopathology support for innovative and cross-disciplinary GI and liver research. Core B, which is located at the Beth Israel Deaconess Medical Center (site 1) and Boston Children?s Hospital (site 2) has the following Specific Aims: 1) to provide access to resources, technologies and services unavailable in members' labs, or inaccessible in other institutional cores; 2) to extend the resources of HDDC investigators by subsidizing the costs of services, materials and equipment use; 3) to enhance the technical capabilities of established and young HDDC investigators through training in advanced technologies; and 4) to research, develop and acquire new and emerging technologies that will accelerate digestive diseases research now and in the future. In the past 5-year funding cycle, seven services were offered for Core B. Sixteen or more HDDC members used one or more of the Core B services in every quarter as measured in billable hours of service. HDDC support significantly extended grant dollars by reducing the cost of services by 25% or more for HDDC members and more than 80 papers primarily benefited from core B use. New innovations and equipment updates in the past funding cycle benefited, in particular, the electron microscopy and confocal microscopy services and their users. In the next funding cycle, two new services are proposed for core B including advanced microscopy instrumentation and animal histopathology support. The electron microscopy service intends to add capacity for high pressure freezing/freeze substitution and the confocal service will add new instrumentation and the capacity for ratio imaging. Overall, fifty eight HDDC Members anticipate use of Core B in next funding cycle. Discounted services for HDDC members will continue to extend grant dollars and priority access for HDDC members to core services should facilitate greater productivity.